Micrometer-caliper square.



F. S. BUCKMINSTBR. l vIsciIGRoMB'lJsR GALIPBB SQUARE.

APPLIOATIONAFILED JAN. 17, 1907.

Patented Jan. 12, 1909.

Rs co, wAsHmmfoN. n. c.

UNITED STATES PATENT OFFICE.

FRANK S. BUOKMINSTER, OF PASADENA, CALIFORNIA.

MICROMETER-CALIPER SQUARE.

T o all 'whom it may concern:

Be it known that I, FRANK S. BUCK- MINsTnR, al citizen of the United States, residing at Pasadena, in the county of Los I Angeles and State of California, have invented new and useful Improvements in Hicrometer-Caliper Squares, of which the following is a specification. Y

My invention relates to that class of measuring instruments which have a fixed jaw and a movable jaw, together with a micrometer; and an object thereof is to provide an instrument having a movable jaw that is capable of instant adjustment from one point on the scale bar to another.

A further object is to provide an instrument having a movable jaw capable of instant adjustment which can be locked in the desired posit-ion after the adjustment has been obtained.

I accomplish these objects by means of the device described herein and illustrated in the accompanying drawings, in which Figure 1 is a side elevation of my improved instrument. Fig. 2 is a longitudiy and revolubly mounted in this channel is a threaded spindle 7, one end of which is in revoluble engagement with a iiXed jaw 8 secured to the end of the scale bar 5, the other end of the spindle being revolubly 1 mounted in a bearing 9 secured to the other end of the scale bar 5. Rigidly secured to a pin 10 by means of a wedge-shaped washer 12 is the usual micrometer head 11. The perimeter of the micrometer head is knurled f on its outer edge and is provided on the inner edge with the usual reading scale 13.

Mounted on a scale bar 5 is a movable aw 14 provided with a rectangular opening 15,

the upper face of which is provided with a threaded portion 16 that engages the threaded spindle At each side of threaded portion 16 is a groove 17 adapted to engage the upper edges of the scale bar 5 which form guideways for the movable jaw 14. The side faces of the movable jaw 14 are provided Specification of Letters Patent.

Application led January 17, 1907.

Patented Jan. 12, '1909. serial No. 352,824.

with vertically disposed rectangular openings 18 in which are mounted the arms of a clamp bar 19. The ends of the arms of bar 19 are turned inwardly and engage grooves 20 on the sides of scale bar 5. portion of jaw 14 is provided with a vertical cylindrical recess 21, the bottom of which has a cylindrical opening 22 of less diameter than the recess 21. Mounted in recess 22 is a clutch 23 composed of two members 24 and 25, each provided with a cylindrical recess 26 and 27. The oppositely disposed lower sides of member 24 are cut away to form engaging tongues 28 which are adapted to engage jaws 29 of similar configuration formed in the upper portion of member 27. Clutch members 24 and 25 are normally held from engagement by coil spring 30. The lower of member terminates in a pin 31 of approximately the same diameter as the aperture 22 in clutch member 25 through which it passes. Rigidly secured to pin 31 is a knurled thumb nut 32 by means of which the jaws in member 25 may be turned out of engagement with the tongues 28 of the upper member when it is desired to move jaw 14 by means of the spindle 7. The lower portion of the movable jaw 14 adjacent the cylindrical recess 21 is provided with a transversely mounted pin 33 which engages the vertical groove 34 in the upper member 24 and prevents rotation of the member. rlhe sliding jaw is provided with the usual reading or indicating edge 35.

The operation of the'device is as follows: Should the movable jaw of the square be in the position as indicated in Figs. 1 and 2 of the drawings and it is desired to measure something of a less diameter than an inch, instead of rotating the spindle 7 to bring the jaw to the required distance, the knurled nut 32 is turned so as to bring the jaws 29 into register with the tongues 28 of the upper member of the clutch. The lower member 25 of the clutch together with the sliding jaw is forced upwardly so as to disengage the cylindrical threaded groove 16 from the spindle 7. The jaw can then be moved toward the required division instantly, thus resulting in a saving of time and trouble. After the slidable jaw has been brought to the required division the knurled nut 32 is turned so as to throw the jaws 29 of the lower member out of register with the tongues 28 of the upper member,

The lower@ 60 thus 'locking the movable jaw against any movement except that created by the rotation of the spindle.

Having described my invention what I claim is l. In a device of the class described, a bar; a screw threaded spindle journaled on said bar; a movable member mounted on said bar and adapted to engage With said spindle; a two membered clutch, one clutch member .being mounted in said movable member, the

other clutch member being in sliding con- .neotion with said bar; and resilient means to normally actuate the members of said clutch Ato resiliently hold said movable member in `engagement'With Asaid spindle.

2. :In a device of the class described, a

lscaleibar; a fixed jaw mounted on one end of said scale bar; a screw threaded spindle journaled on said bar; a movable jaw mounted on said vbar and adapted to engage with said spindle; a clutch Whose members are provided with tongues and recesses adapted to interlock; one member of said clutch being revolubly mounted on said movable jaw, the other being in sliding engagement With said scale bar; and resilient means adapted to normally hold said members apart from each other.

In Witness that l claim the foregoing I have hereunto subscribed my'name this 5th day of January, 1907.

FRANK S. BUCKMINSTER.

itnesses EDMUND A. STRAUSE, M. A. JONES. 

